Core drilling for exploration purposes is usually performed with rock drill rigs, wherein the drill string components are placed in the active drill string position, lifted up from or lowered down in the drill hole with the aid of a winch. The winch wire is fastened to the uppermost drill string component with the aid of a lifting plug. Since core drilling aims to extract a drilled-out core of rock to be investigated, tubular drill string components are used. During lifting up of the drill string, which is performed frequently for exchange of drill bits, the string of tubes is lifted unit by unit, whereby the separate tubes are loosened from each other with the aid of the rotator device of the drill rig in co-operation with a lower tube holder.
Final loosening of a tube to be taken away from the drill string is today at least partly performed manually by the operators, wherein this handling includes final threading-off and lifting and guiding of the tube to an area of a tube magazine.
During lowering the drill string, the working steps are performed reversely such that new drill string components in the form of tubes are successively lifted to a position where they are aligned with the drill string and threaded together by the operator. These working steps are stressful and brings about a not negligible risk of being subject to lifting and clamping injuries for the operator.
Core drilling is often performed to very great depths, such as for example to drill length between 1000-2000 m. Because of the drill bit in operation being subjected to wear, it has to be exchanged relatively often, which results in that the entire drill string has to be lifted out from the drill hole, be dismounted into drill string components, the worn drill bit be removed and be replaced by a new one, whereupon the drill string can again be lowered down into the hole. Thereupon a further distance is drilled until the drill bit has to be exchanged again etc. During the drilling, a flushing liquid swivel is connected to the uppermost end of the drill string for supplying flushing liquid for transporting away rock material having been disintegrated during drilling.
Aim and Most Important Features of the Invention
It is an aim of the invention to provide a device of the above kind, wherein the problems according to the above are addressed and at least partly solved. This is achieved in respect of a handling device according to the above in that the gripper unit is swingably supported around a first swing axis in the region of the feed beam between:
a) a first position aligned with said active drill string position, and
b) a second position aligned with a delivering position for drill string components to be placed into and removed from said active drill string position,
wherein the handling device includes a swing arm, having support means for supporting a drill string component and which is swingable around a second swing axis between a loading position for drill string components and said delivering position, wherein a guiding beam is fastenable at its end regions in connection with the respective regions of the first and the second swing axis, and wherein the guiding beam forms mechanical stops for the gripper unit in said second position as well as for the swing arm in the delivering position.
Through the swingability of the gripper unit it is obtained that in the first position it is arranged to actively align end portions of drill string components to be joined to each other. Hereby it is possible to achieve overall accurate alignment between drill string components, to be joined, and to be separated, safely allowing adequate handling of drill string components during the threading operations and avoiding thread damages, which can be the result of erroneous thread joining attempts. It is also important that threading apart is aligned and controlled.
Through the swingability to the second position, it is obtained that the gripper unit in this second position will be capable of engaging an end portion of a drill string component in the delivering position in order in this position, in a corresponding way, to provide alignment before threading on and threading off of a lifting plug or a flush liquid swivel (in case of a last drill string component of the drill string) on to or off from the gripped drill string component. The gripper unit thus provides fastening of a lifting plug or a water swivel on the drill string component in the delivering position.
The swing arm of the handling device provides that a supported drill string component is swung from a loading position for drill string components, which e.g. suitably is a horizontal position, to said delivering position, which usually is an inclined position of the supported drill string component.
The drill string component can be transferred manually or through any per se known transport method to the loading position. In the delivering position thereupon aligned co-operation with the gripper unit in its second position is provided.
In order to effectively and safely ensure accurate alignment between the gripper unit and the drill string component being supported by the swing arm, according to the invention, a guiding beam is arranged which forms mechanical stops for the gripper unit in said second position as well as for the swing arm in the delivering position. For this purpose, the guiding beam is fastenable at its end regions in connection with the respective regions of the first and second axes. This arrangement results in that the guiding beam in each adjustment position of a drill rig, for example with different inclinations of the feed beam, with varying inclination of a support for the rig, and different vertical positions of the parts of the rig, more or less automatically can provide on the one hand setting references through said mechanicals stops, on the other hand more or less automatically also provide suitable end positioning of the drill string component being carried by the swing arm in respect of the gripper unit.
The invention results in major advantages when it comes to handling. It should be noted that the alignment requirements for threading together drill string components for core drilling are very strict. Thus is not tolerated an alignment deviation of components to be threaded together of more than 1°. Greater angular deviations most likely results in failing threading and in more serious cases to thread damage.
It is preferred that the guiding beam is pivotally attachable around the first pivot axis in connection of an area of the first swing axis and in particular that the first pivotal axis is at least essentially co-axial with the first swing axis. Likewise it is preferred that the guiding beam is fastenable so as to be pivotal around a second pivot axis in connection with a region of the second swing axis, and particularly that the second pivot axis is at least essentially co-axial with the second swing axis. These arrangements one by one facilitates and can, particular taken together, even eliminate the need of adjusting the guiding beam and/or therewith co-operating means on the gripper unit respectively the swing arm after repositioning of the rig or even in case of an unintentional movement of the rig or of the support (such as the magazine) for the end of the guiding beam which is facing away from the rig.
In a first position of the gripper unit it is positioned to engage an end portion of a first drill string component respectively an end portion of a second drill string component. In the second position, the gripper unit is positioned in order to engage aligned with an end portion of a drill string component to be brought into respectively is in the process of being taken out from said active string drill position.
Suitably the guiding beam, i.a. for manufacturing purposes, has linear extension.
Preferably the swing arm and/or the gripper unit in a respective distal region, opposite to a region of the respective pivot axis, have abutment elements for alignment contact with abutment means on the guiding beam in said delivering position. Suitably at least one of said abutment elements and said abutment means is adjustable for adjustment of alignment position.
Preferably the swing arm and/or the guiding beam includes mutual guiding elements for lateral alignment of the swing arm in the delivering position in order, to a certain degree, to eliminate an effect of a mutual lateral obliqueness of the swing arm in respect of the guiding beam.
It is preferred that the guiding beam is provided with a longitudinal guide and a gripper shuttle being drivingly moveable along the longitudinal guide, said gripping shuttle being provided with a pivotally arranged guiding gripper for guiding a first end region of a drill string component, the other end region of which being arranged to be engagement with a lifting plug. This arrangement essentially facilitates handling during the process of lifting with a lifting wire and of applying a drill string component into the drill string position as well as during the process of lifting and removing a drill string component from the drill string position. No corresponding guiding is in principle provided according to the background art, but instead it is up to the operator to see to that, in the most uplifted position of the drill string component, when it hangs in the lifting wire, accurate positioning into the drill string position is made and an adequate removal from the drill string position to a delivering position for further transporting. The arrangement with a gripper shuttle instead allows safe and accurate guiding of a free end of a lifted drill string component in the respective position.
The invention also concerns a rock drill rig including a rotator device for rotation and driving of a drill string and being moveable to and fro supported by a feed beam and a handling device according to the above.
The invention further concerns a method for handling drill string components in respect of a rock drill rig. This method is distinguished in that the gripper unit is swung around a first swing axis in the region of the feed beam between:
a) a first position aligned with said active drill string position, and
b) a second position aligned with a delivering position for drill string components to be placed into and removed from said active drill string position,
wherein a swing arm, having support means for supporting a drill string component is swung around a second swing axis between a loading position for drill string components and said delivering position, and wherein a guiding beam being fastenable at its end regions in connection with the respective regions of the first and the second swing axis, and wherein the guiding beam mechanically stops the gripper unit in said second position as well as the swing arm in the delivering position.
The advantages indicated above in respect of the inventive handling device and the subordinate features are applicable also in respect of the inventive method.
The invention will now be described in greater detail by way of embodiments and with reference to the annexed drawings.